Circuit breaker-hold-in mechanism



Sept. 7, 1948. w. M. SCOTT, JR

CIRCUIT BREAKER-HOLD-IN MECHANISM 5 Sheets-Sheet 1 Filed Sept. 29, 1943 2 a M m 55 4 J 2 L WWMMW w Q Z 74 1/ M u 6 6 y w /w 2 a 8 8 g N m M Z w W INVENTOR MA /WMJC TTr/Q ATTORNEY P 1943- w. M. sco'r'r, JR 2,449,013

CIRCUIT BREAKER-HOLD- IN MECHANISM Filed Sept. 29, 1943 5 Sheets-Sheet 2 WORM 1L Hg. 3 i" INVENTOR mum/1M1 Jcorrae. i B

ATTORNEY p 7, 1948. w. M. sco'rr, JR 2,449,013

CIRCUIT BREAKER-HOLD- IN MECHANISM Filed Sept. 29, 1943 5 Sheets-Sheet 4 INVENTOR ATTORNEY P 1948- w. M. SCOTT, JR 2,449,013

CIRCUIT BREAKER-HOLD- IN MECHANISM Filed Sept. 29, 1943 5 Sheets-Sheet 5 Eg 26' 25 24 2a BY Mam AWORA/Ey Patented Sep 7, 1948 UNITED STATES PATENT OFF! 2,449,013 CIRCUIT BREAKER-HOLD-IN MECHANISM William M. Scott, Jr., Bryn Mawr, Pa., assignmto I-T-E Circuit Breaker Company, Philadelphia,'Pa., a corporation of Pennsylvania Application September 29, 1943, Serial No.

18 Claims.

breaker, but which requires constant supervision to eflect the locking function, so that immediately upon release of the hold-in by the operator, the tripping mechanism of the circuit breaker will be unlocked.

Essentially, my invention is designed for use in connection with circuit breakers mounted in dition, it is important to secure every last moment of benefit from critical period. However, as soon as the battle is longer period than is necessary or desirable.

Thus, there are conditions, obtaining during short periods, when the circuit breaker equipment fulness on his release.

subjected during battle conditions are so severe that a manually held locking device having a linear movement such as I pushing a rod would not give the operator willcient mechanical advantage to withstand the shock and the circuit breaker is tripped in spite of the manual holding or lock-in device. This is so, also, because the operator may himself be rocked back by the shock; so that while he may maintain some hold on the locking device handle, his inward pushing force thereon is relaxed.

In accordance with my invention, therefore, the manual lock-in of the circuit breaker is achieved by a rotary motion which is not as responsive as a linear motion to shock and the operator, there-,

breaker locked shock. present invention fore, can manually hold the circuit against the forces produced by the An important object of the is the provision of a lock-in device which can be moved to circuit breaker locking position and which will remain in the locked position only while it is under the direct control of the operator.

Another object of my invention is the arrangement of a circuit breaker lock-in or hold-in device in such manner that the hold-in is effective only when positively manually grasped and becomes ineffective to prevent tripping of the circuit breaker immediately upon manual release thereof.

A further object of my invention is to provide means whereby the manual operation for locking the circuit breaker comprises a rotation which is substantially free of forces of shock.

Still a further object of my invention is to provide means whereby a release of the rotating member by the operator automatically results in restoration of the circuit breaker to non-locked condition.

The hold-in device may be so arranged that rotation of the handle in the direction in which an and so that rotawhich in an ordicircuit breaker against tripping; tion of the handle in a direction nary circuit breaker would be eflective to trip the ranged that even of the circuit breaker is locked against movement, the latch member on which thearmature oi the tripping magnet operates is free to rotate. and thus will not be broken on the occurrence of an overload condition while the hold-in is in effective lock-in position.

My invention also contemplates the provision 01' means whereby the hold-in becomes effective on the movement of the latch member from a position where it may trip the circuit breaker to a position where, even though it rotates, it is ineffective to trip the circuit breaker.

It will be understood that the present invention is applied in circuit breakers having trip free features so that the closing handle cannot be employed as the manual means for holding the circuit breaker closed since the contacts are free of the handle as soon as closing has been effected.

My present invention, accordingly, is largely a development of the invention set forth in my Patent No. 2,412,294 so that the present application is a continuation in part of the said application.

The foregoing and many other objects and characteristics of my invention will become apparent in the following description and drawings in which:

Figure 1 is a side view of a circuit breaker operating mechanism showing a hold-in device connected thereto.

Figure 2 is a top view of the hold-in device and associated parts taken from line 2-2 of Figure 1 looking in the direction of the arrows.

Figure 3 is a front view of the handle of the hold-in device. v

Figure 4 is a cross sectional view, partly in elevation, taken along line 4-4 of Figure 1 looking in the direction of the arrows.

Figure 5 is a cross sectional view, partly in elevation, taken on line 5-5 of Figure 2.

Figure 6 is a cross sectional view through a portion of the hold-in device taken on line 6-6 of Figure 1 and looking in the direction of the arrows.

Figure '7 is a View corresponding to that of Figure 4 showing the operation of the hold-in device of Figures 1 and 2 to trip the circuit breaker so that the latch members move from the position of Figure 5 to the position of Figure 9.

Figure 8 is a view corresponding to that of Figure 2 showing the operation of the hold-in device to lock the circuit breaker against trip- Ping.

Figure 9 is a view corresponding to that of Figure 5 showing the arrangement of the latch members thereof in the tripped position.

Figure 10 is a side view of a slightly modified form of the hold-in device of Figures 1 to 9.

Figure 11 is a cross-sectional view taken on line Il-ll of Figure 10, looking in the direction of the arrows.

Figure 12 is a top view of a further modified form of the hold-in device.

Figure 13 is a back view of the hold-in device of Figure 12 showing further the manner in which the same is integrated with the parts of the operating mechanism.

Figure 14' is a cross-sectional view taken on line i4-l4 of Figure 12 looking in the direction of the arrows.

Figure 15 is a cross-sectional view taken on line l5-l5 of Figure 14 looking in' the direction of the arrows.

- Figure 16 is a side view of a further modified 75 wise direction so though the tripping mechanismright hand corner of-Figure'l'! showing the form of the hold-in device showing the hold-in device operated to the hold-in position.

Figure 1'7 is a top view of the hold-in device of Figure 16.

Figure 18 is a view corresponding to the lower position of the hold-in device when it is not in lock-in position.

Figure 19 is a cross-sectional view partly in elevation taken on line l9-l9 of Figure 16 looking in the direction of the arrows and demonstrating the operation of the centering spring,

. Figure 20 corresponds to that of Figure 19 showing another operation of the centering spring.

Figure 21 is a top view of a modification of the construction of Figures 12 and 13.

Figure 22 is a developed schematic view of a portion of the guide and locking means of Figure 21.

Figures 23, 24, 25, and 26 are schematic views of variations of the guide of Figure 22.

Figure 2'7 is a schematic of to which my invention may be applied.

Referring now to Figure 1, I have here shown a housing 20 for a circuit breaker mechanism. The operating mechanism contained within this housing may be exactly like that shown in my Patent No. 2,412,294 above mentioned. The circuit breaker as a whole may, except for the holdin device hereinafter to be described, be in the form shown in my Patent No. 2,348,228.

It is suilicient to note for the purposes of the present disclosure that the operating mechanism contained within the housing 20 is so arranged that on operation of a suitable manual operating member or of the solenoid mechanism, indicated generally at 2|, the various links and toggles within the housing will be actuated to raise the link 23 so that it will rotate the crank 24 upwardly to effect a closing of the contacts; and that on the tripping of the circuit breaker, the links and toggles within the housing 20 will be moved to a position where the link 23 will no longer be supported in its raised position but will drop in response to any opening bias which is placed on the movable contact member so that the crank 24 may drop.

The links and toggles within the housing 20 may be supported, as pointed out in my two applications above noted, by a primary latch member 25 (see particularly Figure 5) rotatably mounted on the pin 26 and having a notch 21 in which is engaged the latch tip 30 of a latch lever 3|. I

The lower end 32 of the primary latch 25 bears tangentially against the surface of the milled shaft 34. The shaft 34 is milled at 35 substantially through or slightly below the center thereof. The end 32 0f the primary latch 25 bears against the shaft 34 in such manner that it registers with the milled portion 35, but is prevented from entering therein by reason of the fact that the end 32 extends slightly beneath the milled portion.

The tripping of the circuit breaker occurs upon rotation of shaft 34, so that the milled portion 35 is rotated from the position shown by the solid lines of Figure 5 tothe position shown by Figure 9, and so that no solid portion of the shaft, 34 any longer obstructs the entry of the end 32 of the primary latch 25 therein.

' Consequently. as shown in Figure 9, the primary latch 25 is free to rotate in a counterclockthat the end 32 thereof may a circuit breaker enter the milled portion of the shaft :4. This rotative movement of the latch occurs by the latch lever 3| is so Since the latch tip 30 on the lever 3| bears against the lower end of the notch 21, as shown in Figure 5, in a direction to cause rotation of the primary latch 25, this rotation may occur when shaft 34 rotates from the position of Figure 5 to the position of Figure 9.

This entire operation is more clearly and speciflcally described in my two applications above noted, and forms no part of the present invention.

A schematic drawing of the circuit breaker contact members is shown in Figure 27 in which the milled erating with the toggle mechanism 595 which, operating through the arms 595 and 591, operate the movable contact arm 598 which effects the disengagement of the contact 599 from the fixed contact 600.

My hold-in device is entirely designed to co-act with the milled shaft 34 in such manner as to prevent the milled portion 35 from moving opposite the end 32 of the primary latch 25 under tripping conditions.

It may here be noted in passin that the milled shaft 34 is retained in the position of Figure 5 by the spring 40 connected at one end to a lever 4| carried by the shaft 34, and at the other end to any suitable lug 42 on the housing 20.

The position of the milled shaft in the nontripp d position of Figure 5 may be determined by the adjusting screw 43 passing through the lug 44 of the housing and held in p ace by the lock nut 45. The insulating member 45, carried by the milled shaft 34, may bear against the adjusting screw 43 to thus determine the position.

The operation which my hold-in device must perform in order to lock the circuit breaker against tripping is clearly seen by a comparison of Figures 2 and 8.

The milled shaft 34 of Figure 2 is shown so arranged that the milled portion 35 thereof is in registry with the primary latch 25; so that on rotation of the milled shaft 34, the primary latch may be caused to enter the milled portion 35.

In order to effect a locking of the circuit breaker against tripping, I ma arrange my milled shaft 34 (as shown in Figure 8) so that it may be moved longitudinally from the position of Figure 2 to the position of Figure 8 wherein the milled portion 35 is moved out of registry with the primary latch 25; so that irrespective of the amount of rotation imparted to the milled shaft 34, the milled portion 35 can never move opposite the primary latch 25; so that latch 25 will always be retained in the position shown in Figure 5 when the shaft 34 is in the position shown in Figure 8.

Essentially, therefore, the hold-in device of my invention must be so arranged that it will cause the milled shaft 34 to move longitudinally from the position of Figure 2 to the position of Figure 8.

My invention contemplates also, that the same hold-in device, in order to avoid unnecessary duplication of parts, may also be arranged that on operation in an appropriate manner, it may be caused to rotate the milled shaft 34, while the said shaft is in the position of Figure 2 in order to effect a tripping operation of the circuit breaker.

In Figures 1 to 9 I have shown one type of hold-in device which embodies the principles of my invention.

The hold-in device consists of a longitudinally slidable rod 50 and a handle 62 connected thereto for operating the same. Rod 50 is mounted for rotatable and longitudinal movement in the bearings 52, 53 of the hold-in frame 54. The said hold-in frame is secured to the side of the housing 20 in any suitable manner as, for instance, by the bolts II.

The end of the rod fits into the similarly squared socket 6| in the back of the rotatable handle 62. The handle 62 (hereinafter more fully described) is mounted so that it may freely rotate but is arranged so that it will not move longitudinally. Although the rod 50 will move longitudinally on rotation of the handle 62, it will be able to slide in and out with respect to the socket 6| of the handle 62, while the squared end 60 in the socket will always ensure will be under the control of the handle.

Thus, despite the fact that the handle does not move in and out, rotation thereof will, in the manner hereinafter described, cause the rod to move in and out.

The handle 62 may be mounted in any suitable manner so that it may rotate without moving longitudinally. One method of mounting the same is the formation of an annular groove 64 in the body of the handle which will register with an opening 55 in a front frame where the material defining the opening 65 may enter into the groove. For this purpose, as shown in Fig-v ure 1, the handle 62 her 10 recessed to define the flange 64 and secured to the portion 62 by the bolts 7|, II. This method of securement will permit the handle readily to be removed for replacement or repair. It should, however, be borne in mind that this type of operation of the handle is solely for the purpose of confining the manual operation to a simple rotative movement to effect a hold-in.

Should the handle 62 be directly secured to the end of the rod 50 (rather than simply being keyed thereto), then the operator, in addition to rotating the handle, will either push the handle in, or find that on rotation the handle moves inwardly.

While the first type of handle mounting is preferred, the second type of handle mounting is fully operative in connection with my invention.

Essentially, as shown by a comparison of Figures 1, 2 and 8, the rod 50, in order to effect a hold-in operation, should move from the position of Figuresrl and 2 to the position of Figure 8. This kind of operation is achieved, as will be obvious from a comparison of Figures 1 and 8, by the stationary key 80 registering in the spiral groove M of the rod 50.

The key 80 may simply be an adjustable screw passing through an appropriate threaded opening in the base of the frame 54 and being held in its proper relation by a lock nut 82. The end of the screw 80 enters into the the lock position thereof, the rod 50 is similarly rotated through On such rotativemovement, since the sides of the spiral groove 8| in the rod 50 is squared off and that the position ,of the rod may have an inner mem v 50 cannot escape from the key member 00, the rod 50 will slide so that the, with successive portions of the groove the end 04 thereof to the end 05.

This camming arrangement by the use of the spiral groove 8| causes the rod 50 to move from the position of Figures 1 and 2 to the position of Figure 8.

This longitudinal movement of the rod 50 is translated into longitudinal, movement of the milled shaft 34, as shown by a comparison of Figures 2 and 8, by a bell crank lever 90.

The bell crank on the pin 9|, which in turn is supported by a lug 92 secured to the wall of the housing 20.

A clevis 93 on one end of the bell crank lever is captured on the extension 94 of the rod 50 between the plates 95 and 95 so that the bell crank lever must necessarily rotate about its pin 9I in response to the longitudinal movement of the rod 50.

A clevis I'0I on the opposite end of the bell crank lever 90 is engaged on the extension I02 of the milled shaft 34 between the plate I03 and the end I04 of the milled shaft itself.

Consequently, any rotative movement of the bell crank lever 90 about the pin 3| in response to longitudinal movement of the rod 50 will be translated into longitudinal movement of the milled shaft 34.

When the rod 50 is in the normal posiion of Figures 1 and 2 with the handle in the position of Figure 3, then the milled shaft 34 is in position, as shown in Figure 2, where the milled portion 35 is opposite the primary latch member 25, so that on rotation of the milled shaft 34, a tripping operation will occur.

On rotation of the handle 62 from the normal position of Figure 3 to the lock position of Figure 3, the rod 50 moves from the position of Figure 2 to the position of Figure 8; and the milled shaft 34 is correspondingly moved along its axis so that the milled portion 35 moves out of registry with the primary latch 25.

Consequently, the end 32 of the primary latch 25 can no longer enter the milled portion 35 of the milled shaft 34 in response to overload conditions irrespective of the degree of rotation of the milled shaft 34.

Thus, should the circuit breaker be subjected to an over-current condition or to a violent physical shock causing a vibration or rotation of the shaft 34, the primary latch 25 cannot enter the milled portion 35, and the circuit breaker cannot be falsely tripped.

The hold-in device is intended to remain opreative only as long as the handle 02 is amrmatively manually held in the lock position of Figure 3. A resetting spring H is, therefore, provided in order to accomplish this result.

The resetting spring IIO, as seen in Figures 1 and 2, and especially in Figure 6,-i-s a coil spring which is coiled around the rod 50. The upper end III of the spring passes through an opening H2 in a vertical lug II3 of the rod 50, while the lower end I I6 of the spring I I0 passes through a similar vertical lug III 180 removed from the lug H3. The end III of the spring bear against the upper portion I of the housing for the hold-in device; and the and N3 of the sprin bears against the lower portion I2I of the housing 54.

On rotation of the rod 50 in a clockwise direction with respect to Figure 6, the lug H3 bears against the end III of the spring and tensions 3i from key will register lever 90 is rotatably mountedthe same; while the opposite end N3 of the spring, bearing against the surface I2I. assists in maintaining this tension.

Consequently, upon release of the manually applied rotative force, the end III of the spring biases the rod 50 back toward the position of Figure 6, and thus back to its normal position.

Similarly, when the rod 50 is rotated in a counterclockwise direction with respect to Figure 6, the lug I I1 bears against the end I I6 of the spring and tensions the same, while the upper end III is held by reason of the fact that it bears against surface I20. Again, on release of the manually applied rotatlve force, the rod 50 will be biased back to its original position.

Consequently, when the operator of the holdin device rotates the handle 62 from the normal position of Figure 3 to the lock position of Figure 3, thus moving the parts of the circuit breaker mechanism from the position of Figure 2 to the position of Figure 8, the lock position and the position of the elements shown in Figure 8 will be retained only as long as the operator aflirmatlvely holds the handle in the lock position. Immediately upon the removal of this holding pressure, the spring I I0 will cause the rod 50 to rotate back from the position of Figure 8 to the positions of Figures 1, 2 and 6, thus restoring the milled shaft 34 to the position shown in Figures 1, and 2. By this means, therefore, the hold-in mechanism is effective to lock the circuit breaker against tripping only as long as the operator maintains his hold on the handle 62.

It is obvious, of course, that the milled shaft 34 is so arranged as to slide longitudinally in bearings carried by the housing 20. Thus, as shown in Figures 2 and 8, the milled shaft 34 has extensions I25 and I30 which are rotatably and slidably mounted in the bearings I3I and I32. Each of the extensions I25 and I30 is provided with a broad lever I33 and I34 which may readily be engaged by the armature of the tripping magnet or by elements operable thereby.

It will be obvious that the tripping armature need only rotate the extensions I33 and I34 in a counterclockwise direction with respect to Figure 1 in order to effect the tripping operation.

In order to provide for manual tripping, the extension I30 also carries a lever I40, as shown in Figures 1, 2 and 8. The said lever I40 is keyed to the extension I30, so that rotation of the lever I40 downwardly will result likewise in counterclockwise rotation of the milled shaft 34.

The handle 52 and the rod 50 may be arranged so that on rotation thereof in a direction opposite to the direction of rotation for looking, a tripping operation may be obtained. The successive steps of this operation will be obvious from an inspection of Figures 4 and 7.

The shaft 50 is provided with an extension I50 at the inner end thereof, the said extension I50 also servin to support the extension 94 which has previously been described.

Extension I50 is eccentrically connected to the rod 50, as shown particularly in Figures 4, 7 and 8, but is so connected to the extension 94 and its plates and 96, that the extension 94 is concentric with the rod 50.

The eccentric extension I50 passes through a slot I52 in the lever I53. Lever I53 is rotatably mounted on the pin I54 carried by the housing 54 of the hold-in device. Surface I55 of the lever bears against the upper surface of the extension or lever I40 of the milled shaft 34.

On rotation of the handle 62 from the normal position of Figure 3 to the trip positionof Figure 3, the rod 50 wil be rotated from the position shown in Figure 4 to the position shown in Figure 7, so that the eccentric extension !50 thereof will move from the position of Figure 4 to the position of Figure 7 and thus cause a rotative movement of the lever !53, thus pressing the surface I55 thereof down upon the upper surface of the extension I40 of the milled shaft 34 and effecting a rotation of the milled shaft for .trlpping purposes. 6

The spring H0, previously described, will return the rod and the handle 62 back -to the original position immediately upon the removal of the manual holding force from the handle.

It will be obvious from an inspection of Figure 1 that while rotation of the handle in the direction to lock the circuit breaker will cause the rod 50 to rotate so that the groove 8! may slide along the key 80 and move the rod longitudinally, nevertheless, on rotation in the opposite direction, the rod 50 must be free to rotate without neces sarily sliding longitudinally in order to eifect the tripping operation.

Consequently, a concentric groove I60 is providedin therod 50 adjacent the rear end of the spiral groove 8! and extending in a direction opposite thereto so that the simple rotation of the rod 50 in the tripping direction will not be in terfereli with.

By the means herein shown, I have provided a circuit breaker hold-in mechanism which is manually operable to prevent the circuit breaker from tripping in response to physical shocks and which may be operated, if desired, to prevent the circuit breaker from tripping in response to said overloads. This hold-in device, however, is so arranged that on removal of the operator's hand from the handle, the hold-in is immediately reset to its normal position and is no longer operative to prevent trippin of the circuit breaker.

In order to facilitate the operation of the holdin device, I have arranged the members so that rotation of the handle in a clockwise direction (which is the direction normally used in circuit breakers for closing a circuit breaker) will serve to lock the circuit breaker against tripping, while rotation of the handle in a counterclockwise direction (which is normally the direction for openin the circuit breaker) will serve to trip the circult breaker.

Consequently, the possibility that an operator may be confused under stress is greatly diminished, since the operations to be performed by him are the normal operations in the directions to which he is accustomed in order to obtain the various results desired.

My invention is susceptible of many modifications of which some of the preferred forms are hereinafter described.

In Figure 10 I have shown one modified form of my device which is only slightly different from that shown in Figures 1 to 9. In this figure, the rod 25!! has essentially the same operation both for hold-in and tripping purposes as does the rod 50 of Figures 1 to 9-that is, the extension 294 thereof is engaged by the clevis 293 of a bell crank lever which operates the milled shaft from a trip position to a lock-in position in the manner described in connection with Figures 2 to 8.

Likewise, the rod 250 is provided with an ex-- tension 22!) similar to the extension I50 of Figure 8 which operates the lever 253 to in turn operate the trip lever 24!) secured to the milled shaft. The rod 250 is thus arranged so that on 10 longitudinal movement thereof, it will have exactly the same operation as the rod 50 of Figures 1 to 9; and so that on rotative movement thereof, it Will also have exactly the same function as does the rod 50 in Figures 1 to 9.

The frame 254 in which the rod 250 is slidably and rotatably mounted is provided with an extension sleeve 255 which completely surrounds the front end of the rod 250. The extension sleeve 255 is provided with a semi-circular slot 256, as seen in the cross sectional view of Figure 11; through which a pin 280 carried by the handle 262 may pass. The handle 262 may thus freely rotate through without being detached from the sleeve 255. a

The pin 280 passing through the slot 256 of the sleeve 255 enters into the spiral groove 28! in the rod 250. The normal position of the members is that shown in Figure 10.

The rod 250 is also provided with a longitudinal keyway 230 into which the screw 23! extends acting as a key therefor. The longitudinal keyway 230 thus confines the movement of the rod 250 to a longitudinal movement.-

Consequently, when the operator rotates the handle 262 in a clockwise direction, the screw 280 bearing against the walls of the groove 28! forces the rod 250 to move longitudinally; this is especially so since the rod 250 cannot follow the rotative movement of the screw 28!) owin to the longitudinal keyway 23!! therein and the key 235 engaging the same.

The coiled compression spring 2l0 has one end 2!! captured in the end of the frame 254 and, the opposite end 2!2 captured in the lug 2I3 on the rod 256. When the rod 250 is moved toward the right with respect to Figure 10, pursuant to appropriate rotation of the handle, the spring 2!!! is compressed. Consequently, immediately upon removal of the operators hand from the handle, the compression spring 2!!! will serve to return all of the parts to the position of Figure 10.

When the handle 262 is rotated in the opposite or counterclockwise direction, it will bear against the inner end of the groove 28! and cause a corresponding counterclockwise rotation of the rod terclockwise from the keyway 230 in a position where it registers with the key 23! in the normal position of the elements of Figure 10.

Consequently, the handle is free to rotate the rod 250 in a counterclockwise direction to effect the tripping operation in the manner hereinbeposition of Figure 10.

In Figures 12 to 15 inclusive I have shown a further modified form of my invention which The milled shaft 334 is, as previously pointed may be provided with a handle shown in Figure 3 positively sethereof and is also provided with such as that shown in Figdescription hereinafter set forth in connection with Figures 16 to 20, so that the rod 355 will automatically return to the normal position upon the removal of the operator's hand from the handle thereof.

The milled shaft 333 is constructed essentially in the same manner as is the milled shaft 3d of Figures 1 to 9. Thus, in its normal position, so that it may readily operate the circuit breaker in response to overload conditions, the milled portion 335 thereof is in registry with the primary latch 325.

When rod 353 is thus rotated in such manner as to move the milled shaft 333 to the left with respect to Figures 12 and 13, the primary latch member 325 will thus be opposite a solid portion ,of the shaft 335, and thus no tripping operation can take place in response to movement of the shaft as previously described. The shaft 333 is,

however, provided with an additional milled portion 380.

As will be seen from Figures 12 and 13, the milled portion 380 is immediately adjacent the milled portion 335 and is deeper milled. This deeper milling of the milled portion 303 will more readily be seen in Figure 15 where it will be obvious that the section 380 is milled so that it extends beyond the engaging tip 322 of the primary latch 325. The surface of the milled portion 380 need not be parallel to the surface of the milled portion 335-. It is sufficient, as seen in Figure 15, that the end thereof adjacent the tip 322 of the latch 325 be lower than the tip 322 to permit entry of the tip into the milled section.

It will now be obvious, therefore, that on rotation of the shaft 350 in a direction to move the milled shaft 334 to the right with respect to Figures 12 and 13, the deeper milled portion 380 of the shaft 334 will be moved opposite the tip 322 of the latch 325, and the latch member will then enter into this milled portion and effect a tripping of the circuit breaker.

Consequently, the same device may be operated by rotation in one direction to cause the shaft 334 to move longitudinally to lock the circuit breaker closed, and by rotation in the opposite direction to cause the milled shaft to move longitudinally in a reverse direction to trip the circuit breaker.

A handle, as above pointed out, should be securely attached to the end of the rod 350. The only element that need directly cooperate with the rod 350 is -a' centering spring of the type hereinbefore or hereinafter described.

No additional levers or bell crank members are necessary, since the motion in either direction is translated through a rack and pinion arrangement.

While in Figure 13 the rack 395 is shown as made up of a series of completely circumferential grooves, it will, of course, be obvious that this rack may be formed by a series of grooves which operation crank lever extend only over a portion of the circumference of the extension 302 as determined by the degree of rotation necessary for the milled shaft 334 which, as will be clear, is rather limited.

In Figures 16 to 20 inclusive, I have shown a further modified form of hold-in device utilizing the principles previously set forth.

' Here, the rod 450 has substantially the same as that previously described in connection with Figures 1 to 11. The handle 432 is rigidly secured to the rod 450 so that the rod will rotate on rotation of the handle.

The device shown in Figures 16 to 20 is quite similar to that shown in Figures 1 to 9 with the distinction, however, that the end of the bell previously described registers with a spiral groove in the'rod 350 so that the shaft itself need not slide longitudinally.

In the case of Figures 16 to 20, the shaft $50 is rotatable only in the bearings 455, 455 of the housing 353. The inner endof the shaft 150 is provided with a spiral groove iti within which the key 353, constituting an extension of the bell crank lever 390 normal thereto, engages. v As was previously described, rotation bell crank lever 1390 about its pin GM will result in movement of the milled shaft em from a position where the circuit breaker may trip in response to overload to a position where the primary latch cannot enter the milled shaft 435 thereof.

On rotation of the rod ment of the walls of the groove 4!" with respect to the key 430 will cause the bell crank lever 490 to rotate about its pin dill from the position of Figure 18 to the position of Figure 1'7, thus efiecting the hold-in operation in the manner previously described.

As will be clear, the bell crank lever 490 may be provided at its end with opposite keys 480 registering with opposite grooves 436 in the rod 450, although, this latter expedient is not essential to proper operation of the device.

The engagement between the bell crank lever 490 and the milled shaft 434 is through the clevis arrangement 40! previously described. Rotation of the rod 450 in the opposite direction will serve to rotate the milled shaft 434 in a tripping direction by reason of the engagement of the lever 453 with the extension 440 of the milled shaft 434. v

The lever 453 is rotatably mounted at 404 and is provided with a slot 405 through which the eccentric extension 406 of the rod 450 passes. The operation of the rod 450 so that the lever 453 will engage the tripping lever 440 is exactly that which was previously described in connection with Figures 4 and 7 and will not here be repeated.

It is suflicient to point out that the eccentric extension 406 serves to carry the section 401 of the rod'450 in which the groove 48l is locked. It will be obvious that in order to permit rota- 450, the relative move- -tion of the rod 450 in an opposite direction (to the hold-in direction) for tripping purposes, a concentric slot 460 may be provided adjacent the outerend of the groove "I so that the key 480 may slide therein, and so that the rod 450 may rotate to the tripping position without moving the milled shaft 434 longitudinally.

A centering spring 0 is provided in order to return the rod 450 to its normal position immediatelyupon removal of the operator's hand from the handle 452. Centering spring 0 is coiled around the rod 450 and is provided with an ex- 13 tension 4| I which passes on one side of lug 2 extending from the rod 450 and on .the same side of the vertical lug 3 which depends from the upper end of the frame 454.

The-opp site end of the spring is also provided with an extension 4 which crosses under the extension I and is bent around the opposite sides of lugs H2 and H3.

The outermost ends of the extensions 4| I and 4| 4 of the spring 4M may be provided with short reentrant bends M5 and 5 to ensure that these extensions will always be in engagement with the lugs.

0n rotation of the rod 450 in a clockwise direction, as shown in Figure 19, the lug 4|! of the rod 450 will bear against extension 4. of the spring and carry it around to the dotted line position of Figure 19, while the extension 4 holds on the stationary lug 3 of the frame. The spring 4H1 is thus tensioned and biases the rod 450 back to its initial position immediately upon removal of the operators hand.

'On rotation of the rod opposite direction to return the rod 450 immediately upon the removal of the operator's hand from the handle thereof.

In Figure 21, I have shown a slightly modified form of the construction of Figures 12 to 15. All of the elements of this figure are the same as those shown in Figures 12 to 15 (and consequently have been given the same reference numbers) with the exception of the locking rod 550 and the spring member and guide means associated therewith.

In this modification, the rod 550 is held against false rotational movement by a yieldinglydisplaceable automatic locking mechanism which ensures that the device will not operate unless specific manual pressure is applied thereto.

Rod 550 is rotatable in bearing 556 of the locking device housing 554. Discs 552 and 553 on rod 594 cooperate with bearing 555 to restrict the rod 594 against longitudinal movement. A

centering spring 560 has one end thereof secured to the lug 56! of the rod 550 and the opposite end secured in the bearing housing 555 of the frame 554. Consequently, any rotation of rod 550 in either direction will tension spring 560 and bias rod 550 toward return to its neutral position.

Housing 554 has a key-pin 510 extending downwardly therefrom into a semi-circular guide slot 580 in the rod 550.

Spring 560 is also a compression spring which drives the rod 550 toward the right and hence causes the key-pin 510 to bear against the left hand wall of slot 580.

As seen in Figure 22, slot 580 is provided with a detent 581 on its left side into which key-pin 510 is pressed by the compression spring 550. Since the pin in the housing 554 is thus engaged,

false operation or rotation of rod 550 is ob-' viated.

In order to operate the hold-in device the operator must now grasp handle 590 mounted on and keyed to rod 550 and pull it outwardly against the bias of compression spring 550 to remove keypin 510 from the detent 58L While thus grasping and pulling the handle 590 he may then rotate the rod 550 to either the hold-in or trip right until key-pin 14 positions in the manner described in connection with Figures 12 to 15.

The handle 590 is therefore shaped (as seen in Figure 21) so that it may readily be pulled out for rotation.

On release of handle 590, the spring 560, acting as a centering spring, will return rod 550 and the associated elements (previously described in connection with Figures 12 to 15) to neutral position and then, acting as a compression spring, spring 580 will drive the rod,550 to the 510 enters detent 58l.

The rod 550 will then be locked against accidental unintendedrotation; while it may readily be released for rotation by an outward pull on handle 590.

In order to insure engagement between the teeth of the rack and pinion 595 and 593 (similar to rack and pinion 395 and 393) as the rod 550 is moved axially, the rod 594 is only loosely coupled to rod 550. This is obtained by making the cross-section of the end of rod 594 square at 558 and having this squared end seat in a square socket 559. By this arrangement as the rod 550 is moved axially, it remains in driving engagemerit with the rod 594 which hasno axialmovement.

Should it be desirable to provide a hold-in which may be rotated to-locking or tripping position and then left in that condition without the necessity for continued attendance by the operator, then the modified slot 580a of Figure 23 may be used. Here. in addition to the neutral detent, 58!, end detents 584 and 585 may be provided. When the hold-in is rotated to either the full looking or full trip position, the key-pin 510 will move opposite detent 584 or 585 as the position to which it has been rotated.

would tend to ride out of detents 584 or 585 so that the rod 550 will return to neutral. Where it is desirable to obtain scribed and shown in my Patent No. 2,412,294.

In Figure 24, I have shown a modified slot 588!) wherein the end detents 584 and 585 are retained for the purposes previously described; but where the central detent SM is omitted, and reliance is placed solely on spring 550 to mainwhere spring 550 is accurate In Figure 25, I have shown a modified form of slot 580c having only one end detent 585; so that the pin 510 may engage therein in the locked position of the circuit breaker for purposes above described.

Such a single detent arrangement may of course also be, used where it is desired to lock the rod 550 only in the tripping position, as where a circuit breaker is to be held open against an erroneous attempt to close it, and where it is not desired to lock the circuit breaker against unauthorized closing but only to trip it open as a warning or reminder to the operator in the event he should attempt mistakenly to close it.

The slot 5800 of Figure may, of course, be provided with a central or neutral detent similar to the detent 5M of Figures 22 and 23 in the event an exact setting for the neutral position is required.

In Figure 26 I have shown a slot 58% without detents but providing an accurate means for determining the plane of movement of pin 5m. Such a slot and pin arrangement may be used, where necessary, to exactly determine the position of rod 550 and its associated elements at all times.

In the foregoing, I have described my invention in connection only with illustrative and preferred embodiments thereof.

Essentially, I have shown a device which is capable of preventing a circuit Joreaker from tripping in response to shock conditions and even in response to overload conditions, should that be desired. v

This device is also operative to trip the circuit breaker open when such an operation is desired.-

The device itself is fool-proof in that when the operator has removed his hand therefrom, it will always return to its normal position where the circuit breaker will no longer be held in locked position. As long, however, as the operator affirmatively holds the handle in the locked position, the circuit breaker will not trip. Thus it is impossible to so operate the device of my invention that the circuit breaker may be left in the hold-in or locked position While the operator withdraws therefrom. In the event of the removal of the operator's hand or in the event of an accident to the operator, the circuit breaker will be restored to the position where it may trip; so that excessive injury to the circuits which are protected by the circuit breaker cannot occur.

My device also embodies many simplified and readily operable hold-in and lock-in elements in order to accomplish the foregoing and many other results. 4

Many modifications and variations of my invention should in view of the foregoing now be obvious to those skilled in the art. Accordingly, I prefer to be bound not by the specific disclosures herein but only by the appended claims.

I claim:

1. In a circuit breaker having a pair of cooperable contacts; means responsive to predetermined circuit conditions for effecting disengagement of said contacts; an axially movable member and a manually operable rotatable member rotatable from a neutral to an operatingposition and connected to said axially movable member,

said axially movable member on moving to one of its positions locking said contacts against disengagement, said manually operable member on being manually released automatically returning to its neutral position.

2. In a circuit breaker having a pair of cooperable contacts; means responsive to predetermined circuit conditions for effecting disengagement of said contacts; and .a rotatable and axially movable member having a neutral position and an operating position to which said member is rotatably and axially moved on the application thereto of a rotating force, means controlled by said member on rotation and axial movement thereof for locking said contacts against disengagement, said member in response to the withdrawal of said rotating force automatically rotating back to its neutral position.

3. In a circuit breaker having a pair of cooperable contacts; means responsive to predetermined circuit conditions for efiecting disengagement of said contacts; a rotatable member having a neutral position, a first-operating position to which said member is rotatable in one direc tion on the application of a force for preventing disengagement of said contacts and a second operating position to which said member is rotatable in the opposite direction of the application of a different force for efiecting disengagement of said contacts.

4. In a circuit breaker having a pair of cooperable contacts; means responsive to predetermined circuit conditions for effecting disengagement of said contacts; a rotatable member having a neutral position, a first operating position to which said member is rotatable in one direction on the application of a force for preventing disengagement of said contacts and a second operating position in the opposite direction to which said member is rotatable on the application of a diiferent force for effecting disengagement of said contacts, and means whereby on the removal of said forces, said member is automatically restored to its neutral position.

5. In a circuit breaker having a pair of cooperable contacts; means responsive to predetermined circuit conditions for effecting disengagement of said contacts; a rotatable member having a neutral position, a first operating position to which said member is rotatable on the application of a force for preventing disengagement of said contacts and a second operating position to which said member is rotatable on the application of a different force for effecting disengagement of said contacts, and a centering spring which on the removal of said forces, automatically restores said member to its neutral position.

6. In a, circuit breaker having a pair of cooperable contacts; means responsive to predetermined circuit conditions for effecting disengagement of said contacts; and a rotatable member having a neutral position and an operating position to which said member is rotatable on the application of a force for effecting disengagement and preventing closing operation of said contacts from disengaged position.

'7. In a circuit breaker having a pair of cooperable contacts; means normally tending to effect disengagement of said contacts; a shaft having a portion thereof milled to a predetermined extent and another portion milledto a different predetermined extent; latching mechanism engaging the edge of said shaft adjacent said first milled portion for maintaining said contacts n engagement against the action of said disengaging means; said shaft being movable axially to bring said latching mechanism opposite said other portion where the extent of the milling is such that said contacts are disengaged, said 17 shaft being also rotatable to bring said latch to the milled portion of the shaft sothat said contacts are disengaged by said first mentioned means.

8. In a circuit breaker having a pair of cooperable contacts; means normally tending to effect disengagement of said contacts; a shaft having a slot cut therein; latching mechanism engaging said slotted portion of said shaft for normally maintaining said contacts in engagement against the action of said first mentioned means and means for moving said shaft axially to move said slot away from said latching mechanism whereby said latching mechanism is rendered ineffective to prevent disengagement of said contacts by said first mentioned means.

9. In a circuit breaker having a pair of cooperable contacts; means normally tending to effect disengagement of said contacts; a shaft having a slot cut therein; latching mechanism engaging said shaft for normally maintaining said contacts in engagement against the action of said first mentioned means and means for moving said shaft axially to present said slot opposite said latching mechanism whereby said latching mechanism is rendered ineffective to prevent disengagement of said contacts by said first mentioned means; and a manually rotatable member for effecting axial movement of said shaft.

10. In a circuit breaker having a pair of cooperable contacts; means for normally tending to effect disengagement of said contacts; a shaft having a slot; a latching mechanism engaging the side of said shaft for maintaining said contacts in engagement, said mechanism when opposite said slot being ineffective to prevent said first mentioned means from disengaging said contacts; means for moving said shaft axially to prevent said latching mechanism from being adjacent said slot; said means comprising a rotatable shaft having a neutral position, a worm and gear connection from said first mentioned to said second mentioned shaft whereby rotation of said second shaft effects axial movement of said first shaft.

11. In a circuit breaker having a pair of cooperable contacts; means for normally tending to effect disengagement of said contacts; a shaft having a slot; a latching mechanism engaging the side of said shaft for maintaining said contacts in engagement, said mechanism when opposite said slot being ineffective to prevent said first' mentioned means from disengaging said contacts; means for moving said shaft axially to prevent said latching mechanism from beingadjacent said slot; said means comprising a rotatable shaft having a neutral position, a gear and rack connection from said first mentioned to said second mentioned shaft whereby rotation of said second shaft effects axial movement of said first shaft; and means whereby on release of the rotating force of said second mentioned shaft, said shaft is automatically rotated back to its neutral position.

12. In a circuit breaker having a pair of cooperable contacts; means for normally tending to effect disengagement of said contacts; a shaft having a slot; a latching mechanism engaging the side of said shaft for maintaining said contacts in engagement, said mechanism when opposite said slot being effective to prevent said first mentioned means from disengaging said contacts; means for moving said shaft axially to prevent said latching mechanism from being adjacent said slot; said means comprising a rotatable shaft having a neutral position and means wherebyrotation of said rotatable shaft effects axial movement of said first mentioned shaft.

13. In a circuit breaker having a pair of cooperable contacts; means for normally tending to effect disengagement of said contacts; a shaft having a slot; a latching mechanism engaging shaft for maintaining said contacts in engagement, said mechanism when opmentioned means from disengaging said contacts; means for moving said shaft axially to prevent said latching mechanism from being adjacent said slot; said means comprising a rotatable shaft having a neutral position and means whereby rotation of said rotatable 14. In a circuit breaker having a pair of cooperable contacts; means for normally tending to eifect disengagement of said contacts; a shaft having a slot; a latching mechanism engaging the side of said shaft for maintaining said contacts in engagement, said mechanism when opposite said slot being effective to prevent said first mentioned means from disengaging said contacts;

said slot; said means comprising a rotatable shaft having a neutral position and means comprising a bell crank connection from said first to said ditions for effecting disengagement of said contacts and a rotatable element having a neutral and operating position operative in response to a predetermined direction of rotation thereof from said neutral position for conditioning said first mentioned means whereby any operation of said first mentioned means by shock will not effect disengagement of said contacts, said rotatable element being operative in response to a reverse direction of rotation for effecting disengagement of said contacts.

16. In a circuit breaker having a pair of cooperable contacts; a shaft having variable degrees of milled portions to lock said breaker contacts contacts against disengagement and cooperating with another of said milled portions for effecting disengagement of said contacts,

17. In a circuit breaker having a pair of cooperable contacts, means including a member having a neutral position and rotatable in response to predetermined circuit conditions for effecting disengagement of said contacts; and a rotatable element operative in response to a predetermined rotation thereof from said neutral position for conditioning said first mentioned means whereby any operation of said first mentioned means by shock will not effect disengagement of said contacts; said rotatable element being rotatable in the opposite direction for effecting disengagement of said contacts, and means operable to automatically center said element in its vertical being effective to prevent said first element being rotatable in the opposite direction for eflecting disengagement of said contacts; said 0 rotatable element being locked in either or its operated positions.

The following refer WILLIAM M. sco'r'r. JR.

REFERENCES CITED file of this patent:

10 Number Name Starr Hill Dorfman et al ences are of record in the UNITED STATES PATENTS Date June 4, 1901 Dec. 27, 1938 Jan. 30, 1942 

